Amp/Preamps vs. High end AV Receivers


Hi,
I am sure this topic had been discussed exhaustively. I am new to this arena looking for some help to upgrade my Onkyo AV Receiver (135 w/channel). I am debating whether to the AV route or the AMP/Preamp combo. Naturally, I understand that I get what I pay for.

Would appreciate some inputs and suggestions regarding:
1. AMP/PREAMP combo route - 
2. AV route

I am not looking at a huge budget but a decent one. 

Thanks in advance
terrancej
B&W CM8 specs:
88dB spl (2.83V, 1m) which is like approximately 86 dB/1 W/1 Meter (quite low).
Impedance: 8Ω (minimum 3Ω) (the minimum does not look good).

Not sure how far you sit from the speakers if one assumes 9ft, you might need for the amp to be at-least putting out 96 Watts of clean watts to reach 85 dB + 15 dB (swings) all the way to 3 Ohm when needed
http://myhometheater.homestead.com/splcalculator.html

So an amp that probably does 200 Watts per channel so that THD is low at 100 Watts, typical of many amps, there are exceptions however.

I don't think there are many receivers that can go up-to 200 Watts per channel and also support impedance to 2 Ohm (at-least on spec).

Better go to with separates for 2 channel an HT bypass will come in handy. This will depend on how you source the music and the music from the videos.
Guys, the OP has 5.1 setup that he uses for both surround sound movies and stereo music playbacks. He only has modest and mediocre B&W CM8 front speakers with a matching center speaker and the B&W CM5 standmount speakers for surrounds. He won’t need very expensive Gryphon Diablo integrated amp or some Vitus Audio or some other expensive electronics. They would be a waste unless if he’s willing to upgrade his speakers.

The Rotel RAP-1580 surround processor amplifier (AV receiver) will suffice it and will be a big step up performance wise or sonically from his Onkyo AV receiver.
I’m pretty sure this Rotel RAP-1580 will satisfy his needs and will pair well with his B&W speakers. Its performance for both stereo music and surround movie playbacks are very good especially coming from an AV receiver. The amplifier section is rock solid and this receiver is heavy weighs in around 54 lbs, unlike those Japanese big box mass produced AV receivers. However, the Rotel RAP-1580 is very barebone when it comes to features and bells & whistles.

Because a very good quality AV separates (av pre pro + multi-channel power amps) will cost him way more than this Rotel RAP-1580 av receiver plus multiple analog interconnects to connect between the two. Of course a good quality AV separates will be better than this Rotel RAP-1580 av receiver or any av receivers but he will need to spend quite a bit if he wants to get good quality AV pre pro and good quality multi-channel amps.

Or alternatively, he could get a good quality stereo integrated amp that has HT bypass and keep his Onkyo receiver for movies or surround duties if stereo is his first priority but it does not seem like he put priority on 2ch.

Even the Cambridge Audio CRX200 av receiver will sound very good on his speaker system. The Cambridge, along with Rotel NAD Arcam Audio Control, make quite musical sounding AV receivers and are quite a bit better than those mass produced Japanese AV receivers eg Denon, Onkyo/Integra, Marantz, Yamaha, Pioneer Elite & Sony.
Dear All,
Thank you all for your inputs and feedback. Much appreciated. I will explore the ideas (along with the budget) and see what is the best option. As one of you indicated, 2ch is not my priority as most of the music videos I listen as well are in 5.1.

I am based out of Atlanta and if anyone is up for a phone chat, please ping me.

Thanks
If this is for 2 channel listening, there are no high end av receivers, too much compromise toward av. I have had a few onkyo/Yamaha av receivers and the  onkyo’s Seemed to have a more warmer sound. 
You will do far better getting an integrated amp like the new yamaha’s for the cheap or go up to the hegel’s for better sound quality. You will still get the built in dacs plus a few other features but the sound quality will be much better for 2 channel